Design of a compact hexagonal structured dual band MIMO antenna using orthogonal polarization for WLAN and satellite applications

In this paper, a compact dual band multiple-input multiple-output (MIMO) antenna system for WLAN and X-band satellite applications (2.4/9.8 GHz respectively) is proposed. On the top face of the substrate, two antenna elements with a size of 20 × 24 mm2 are placed side by side and fed with matched orthogonal micro-strip lines. The two antenna elements have orthogonal polarization which can reduce the mutual coupling between its ports. The designed antenna system is fabricated and measured to validate the simulation results. The impedance bandwidths are about 370 MHz (2.19 to 2.56 GHz) and 630 MHz (9.44 to 10.07 GHz), while the obtained isolation is greater than 14 dB at the operating bands. Furthermore, the envelope correlation is less than 0.052 and 0.008 at 2.4 and 9.8 GHz, respectively. Hence the diversity gain is higher than 9.98 in the frequency bands of interest

Analysis and design of a compact ultra-wideband antenna with WLAN and X-band satellite notch

A compact design of ultra-wideband (UWB) antenna with dual band-notched characteristics based on split-ring resonators (SRR) are investigated in this paper. The wider impedance bandwidth (from 2.73 to 11.34 GHz) is obtained by using two symmetrical slits in the radiating patch and another slit in the partial ground plane. The dual band-notch rejection at WLAN and X-band downlink satellite communication system are obtained by inserting a modified U-strip on the radiating patch at 5.5 GHz and embedding a pair of rectangular SRRs on both sides of the microstrip feed line at 7.5 GHz, respectively. The proposed antenna is simulated and tested using CST MWS high frequency simulator and exhibits the advantages of compact size, simple design and each notched frequency band can be controlled independently by using the SRR geometrical parameters. Therefore, the parametric study is carried out to understand the mutual coupling between the dual band-notched elements. To validate simulation results of our design, a prototype is fabricated and good agreement is achieved between measurement and simulation. Furthermore, a radiation patterns, satisfactory gain, current distribution and VSWR result at the notched frequencies make the proposed antenna a suitable candidate for practical UWB applications

Performance Evaluation of OTFS and OFDM for 6G Waveform

Orthogonal time frequency space (OTFS) modulation is a coming technique addressing the challenges of 5G and 6G. It’s appeared to bring about outstanding error performance in delay – Doppler (DeDo) channels. Still, a really fair comparison with its competitor's direct orthogonal frequency division multiplexing and is extensively used in this participation, we will make a comparison of the performance of OTFS and OFDM with the digital modulation format in terms of bit error rate (BER) versus signal-to-noise rate (SNR) for the 16- QAM technique. From the numerical simulations under MATLAB, the results showed that the OTFS admits a small BER to the OFDM in given case